EPIC data management
and data access on Unix with mSQL database
EPIC data residing on UNIX workstation disks can be managed
with mSQL database for any mSQL supported UNIX system as well
as an INGRES database on an INGRES licensed server machine.
The EPIC database contains metadata from the data files. The
data itself resides in individual disk files and is not entered
into EPIC database. EPIC database contains metadata and pointers
to the individual data files. The data files can be located
at any machine, but loading the EPIC database requires that
the data disks be mounted by the INGRES licensed machine or
mSQL server machine so that metadata from the data file can
be loaded directly into the EPIC database.
Refer to PMEL's EPIC INGRES database
home page for detailed information about INGRES database management.
MSQL is mini SQL, a light weight database engine developed
J. Hughes <firstname.lastname@example.org>
at Bond University, Australia.
It has been designed to provide fast access to stored data
with low memory requirements. As its name implies mSQL offers
a subset of SQL as its query interface. Although it only supports
a subset of SQL, everything it supports is in accordance with
the ANSI SQL specification. The mSQL is a shareware and can
be obtained via anonymous ftp from Bond University, Australia.
The information loaded into mSQL EPIC database includes the
path and name of the data file, geographic range, depth range,
time range, cruise ID, cast number, etc. This information
can be retrieved by a user via the EPIC selection programs
on any networked UNIX machines. The metadata in the mSQL can
be accessed by one the following methods:
The mSQL database engine contains internal RPCs that work
in a client/server environment over a TCP/IP network. The
EPIC/mSQL database data selection program (the client procedures)
send the selection query parameters and search constaints
with RPC calls to the mSQL server machine. When the server
machine receives the message, its service daemon will invoke
the service procedure to search the mSQL database, select
the data file, and then send the result back to the client
procedure. When client procedure receives the message from
the server, the results of the procedures are exracted to
generate the pointer file (list of data files meeting the
users selection criteria) on the local system.
The lastest version of mSQL EPIC database software package
is available in the following ftp directory: